asp.net anchor tag passing query string to a different site

I have a homepage in Kentico 8. On the page, there is a NoticeRepeater which a transformation of type ascx. In the transformation, there is an anchor tag link to external site with markup like:
The customers sometimes are directed to the homepage with a querystring called e_code. If they do, I want the anchor to pass the query string to the external site.
Our company is new to Kentico, and I tried to search online and read the developer doc etc. I have also tried different solutions,could not get it to work.
Basically, something like the following. What did i do wrong? please help, thanks.
{%
if(QueryString.GetValue("e_code") == null){
}else{
<a href="http://someothersite.com?e-code="+QueryString.GetValue("e_code")+" class="btn btn-lg btn-icon-right">
} %}